Category Archives: Marine Resource Management

Stream ecosystems and a changing climate

Examining the effect of climate change on stream ecosystems

Oak Creek near McDonald Dunn research lab. The salamander and trout in the experiments were collected along this stretch of creek.

As a first year Master’s student in the lab of Ivan Arismendi, Francisco Pickens studies how the changing, warming climate impacts animals inhabiting stream ecosystems. A major component of stream ecosystem health is rainfall. In examining and predicting the effects of climate change on rainfall, it is important to consider not only the amount of rainfall, but also the timing of rainfall. Although a stream may receive a consistent amount of rain, the duration of the rainy season is projected to shrink, leading to higher flows earlier in the year and a shift in the timing of the lowest water depth. Currently, low flow and peak summer temperature are separated by time. With the shortening and early arrival of the rainy season, it is more likely that low flow and peak summer temperature will coincide.

A curious trout in one of the experimental tanks.

Francisco is trying to determine how the convergence of these two events will impact the animals inhabiting streams. This is an important question because the animals found in streams are ectothermic, meaning that they rely on their surrounding environment to regulate their body temperature. Synchronization of the peak summer temperature with the lowest level of water flow could raise the temperature of the water, profoundly impacting the physiology of the animals living in these streams.

 

 

How to study animals in stream ecosystems?

Salamander in its terrestrial stage.

Using a simulated stream environment in a controlled lab setting, Francisco studies how temperature and low water depth impact the physiology and behavior of two abundant stream species – cutthroat trout and the pacific giant salamander. Francisco controls the water temperature and depth, with depth serving as a proxy for stream water level.

Blood glucose level serves as the experimental readout for assessing physiological stress because elevated blood glucose is an indicator of stress. Francisco also studies the animals’ behavior in response to changing conditions. Increased speed, distance traveled, and aggressiveness are all indicators of stress. Francisco analyzes their behavior by tracking their movement through video. Manual frame-by-frame video analysis is time consuming for a single researcher, but lends itself well to automation by computer. Francisco is in the process of implementing a computer vision-based tool to track the animals’ movement automatically.

The crew that assisted in helping collect the animals: From left to right: Chris Flora (undergraduate), Lauren Zatkos (Master’s student), Ivan Arismendi (PI).

Why OSU?

Originally from a small town in Washington state, Francisco grew up in a logging community near the woods. He knew he wanted to pursue a career involving wild animals and fishing, with the opportunity to work outside. Francisco came to OSU’s Department of Fisheries and Wildlife for his undergraduate studies. As an undergrad, Francisco had the opportunity to explore research through the NSF REU program while working on a project related to algae in the lab of Brooke Penaluna. After he finishes his Master’s degree at OSU, Francisco would like to continue working as a data scientist in a federal or state agency.

Tune in on Sunday, June 24th at 7pm PST on KBVR Corvallis 88.7 FM, or listen live at kbvr.com/listen.  Also, check us out on Apple Podcasts!

Crabby and Stressed Out: Ocean Acidification and the Dungeness Crab

One of the many consequences associated with climate change is ocean acidification. This process occurs when high atmospheric carbon dioxide dissolves into the ocean lowering ocean pH. Concern about ocean acidification has increased recently with the majority of scientific publications about ocean acidification being released in the last 5 years. Despite this uptick in attention, much is still unknown about the effects of ocean acidification on marine organisms.

Close-up of a Dungeness crab megalopae

Our guest this week, Hannah Gossner, a second year Master’s student in the Marine Resource Management Program, is investigating the physiological effects of ocean acidification on Dungeness crab (Metacarcinus magister) with the help of advisor Francis Chan. Most folks in Oregon recognize the Dungeness crab as a critter than ends up on their plate. Dungeness crab harvest is a multimillion dollar industry because of its culinary use, but Dungeness crab also play an important role in the ocean ecosystem. Due to their prevalence and life cycle, they are important both as scavengers and as a food source to other animals.

Hannah pulling seawater samples from a CTD Carrousel on the R/V Oceanus off the coast of Oregon

To study the effect of ocean acidification on Dungeness crab, Hannah simulates a variety of ocean conditions in sealed chamber where she can control oxygen and carbon dioxide levels. Then by measuring the respiration of an individual crab she can better understand the organism’s stress response to a range of oxygen and carbon dioxide ratios. Hannah hopes that her work will provide a template for measuring the tolerance of other animals to changes in ocean chemistry. She is also interested in the interplay between science, management, and policy, and plans to share her results with local managers and decision makers.

Hannah working the night shift on the R/V Oceanus

Growing up in Connecticut, Hannah spent a lot of time on the water in her dad’s boat, and developed an interest in marine science. Hannah majored in Marine Science at Boston University where she participated in a research project which used stable isotope analysis to monitor changes in food webs involving ctenophores and forage fish. Hannah also did a SEA Semester (not to be confused with a Semester at Sea) where she worked on a boat and studied sustainability in Polynesian island cultures and ecosystems.  Hannah knew early on that she wanted to go to graduate school, and after a brief adventure monitoring coral reefs off the coast of Africa, she secured her current position at Oregon State.

Tune in Sunday June, 17 at 7 pm PST to learn more about Hannah’s research and journey to graduate school. Not a local listener? Stream the show live or catch the episode on our podcast.

Hannah enjoying her favorite past time, diving!

Beyond doom and gloom: highlighting solutions to ocean acidification

When we hear news coverage of global environmental changes, it can easily overwhelm us. We mentally curl up into the fetal position and conclude there is nothing we can do to stave off the changes that Earth is projected to experience. One of these changes is ocean acidification–a phenomenon where carbon dioxide in the atmosphere is absorbed by the ocean. As carbon dioxide levels increase in our atmosphere, more of it is able to dissolve into the ocean and lower its pH, making it more acidic. A decrease of 0.1 pH unit in the global ocean since the beginning of the 1900s may not seem like a lot, but because pH is represented on a logarithmic scale, it actually represents about a 30% increase in hydrogen ions. This makes it harder for organisms like oysters, clams, and corals to build hard shells and skeletons. It is uncertain how this phenomenon could affect the long-term fate of these organisms, as well as the fish that depend on them.

Brian flying in a hot air balloon north of Mt. Rainer, WA.

This is where Brian Erickson comes in. Brian, a masters student in Marine Resource Management in OSU’s College of Earth, Ocean, and Atmospheric Science, observed that most curricula designed to teach high school students about ocean acidification do not discuss actionable solutions that most people can take in their everyday lives to mitigate their carbon footprints. Do student attitudes change when presented with solutions like insulating homes to save on heat, swapping incandescent bulbs with LEDs, or consolidating trips to the store to minimize gas consumption?

Brian at work during his first field biology job, studying the sexual reproduction of tropical seaweeds in St. Croix, U.S. Virgin Islands and San Blas, Panama. It’s easy to fall in love with the ocean when you snorkel on coral reefs for two summers!

A former high school science teacher himself, Brian grew up in St. Louis and received his undergraduate degree in biology from Lewis and Clark College. As an undergraduate, he first became acquainted with environmental research as a field technician in St. Croix in the Caribbean. After participating in Teach For America in New York City, he took many environmental research and education jobs before deciding to return to the ocean to bridge his interests of outdoor education and social science. As his masters draws to a close, Brian will be staying at OSU to begin a PhD in Fisheries and Wildlife working to bring multiple perspectives to marine conservation efforts in East Africa.

Helping students dissect a shark at Bronx Career & College Preparatory High School (Bronx, NY).

Taking students on their first canoe trip with Parks in Focus near Pictured Rocks, MI.

To hear more about Brian’s research and experiences in education, tune in to KBVR Corvallis 88.7 FM at 7 pm on April 15th, or stream it online here. If you’re busy at that time, the show will appear on our podcast later this week.